Lord Falconer, the then-Lord Chancellor, to Alex Salmond, the Scottish FIrst Minister on June 12, 2007. Lord Falconer made clear that the fate of al-Megrahi remained in the hands of the Scottish and that the new warmer relations between the two countries would not affect the bomber.

Jack Straw, who had succeeded Lord Falconer as Lord Chancellor when Gordon Brown became Prime Minister at the end of June 2007 wrote to Kenny MacAskill, the Scottish Justice Secretary, following a meeting where Mr Straw sought an agreement for a "negotiating mandate" for talks witht he Libyans on the proposed prisoner transfer agreement.

A few weeks later, on August 17, 2007, Lord Hunt, at the time a junior minister in the Ministry of Justice wrote to Mr MacAskill in response to a query from the SNP over whether the British Government shared Scotland’s desire to exclude al-Megrahi from the prisoner transfer agreement.

The letters show Mr Straw broke a promise to the Scottish executive not to sign a prisoner transfer deal unless criminal convicted of the Lockerbie bombing were explicitly excluded.

In September, he wrote to Mr MacAskill promising he would include in the negotiating treaty a clause saying that no prisoner convicted of an offence in connection with the Pan Am bombing could be transferred.

Just over two months later, Mr Straw wrote again to say he was unable to "secure an explicit exclusion", although he added that al-Megrahi would not be considered for transfer because he was appealing his conviction, and that the final decision on allowing any transfer remained with the Scots.

In February 2008, Mr Salmond wrote to Mr Straw saying he disagreed with the decision to exclude al-Megrahi from the agreement. The Justice Secretary replied saying that he did not understand his concerns, as the Scot retained the power to veto al-Megrahi’s release.

The Foreign Office also released two letters relating to the case. The first sent by Foreign Office lawyers to the criminal justice directorate in JUly 2009 advised the Scots they would not be breaking an agreement with the Americans by releasing al-Megrahi.

A final letter from Ivan Lewis, a Foreign Office Minister, sent to Mr MacAskill last month, makes clear London did not consider promises made to the American authorities before his trial that al-Megrahi would serve his sentence in Scotland ruled out a prisoner transfer.

The Scottish government also released a set of letters and minutes, including the claims that Bill Rammell, a Foreign Office minister, said neither Gordon Brown nor David Miliband "would want Mr Megrahi to pass away in prison".

They also discussed the possible impact of releasing al-Megrahi to his family home in Newton Mearns with Strathclyde police, including the amount of protection he would need round the clock and how much regular trips to hospital would cost.

A series of meetings between the Scottish government and the Libyan delegation. In particular on March 12, Abdulati Alobidi, the Libyan Minister for Europe, brings up Bill Rammell's visit to Tripoli in February where he state "neither the Prime minister nor the Foreign Secretary would want Mr Megrahi to pass away in prison".